The folded envelope prior art is replete with disclosures of a plethora of "two-dimensional" envelopes, i.e., those in which juxtaposed front and rear walls are articulated directly to one another along score lines and "three-dimensional" envelopes, i.e., those in which the front and rear juxtoposed walls are connected by side walls to provide the envelope with depth or bulk. In all of these envelopes, many different sealing and opening arrangements are employed incuding those for preventing premature or unauthorized opening of or tampering with the envelopes, for facilitating sealing of the envelopes, for facilitating reuse of the envelopes through reclosable construction features, etc.
The present invention is directed to a simplified envelope construction in which the glue flaps used to complete the initial envelope structure are adhered to the major envelope panels by a special "bimodal" type of adhesive, which may be subsequently heat activated for the adhesion of an overlying closing flap to one of the major panels through special openings or apertures formed in the glue flaps. These openings are positioned in registry with the underlying stripes of adhesive and the overlying areas of the closing flaps which are to be contacted by the heat-activated adhesive. This new construction simplifies the manufacture and use of envelopes, especially envelopes of the type ordinarily used to package delicate articles, such as hosiery.
For a better understanding of the principles of the present invention and a more complete appreciation of the attendant advantages derived from its practice, reference should be made to the following detailed description taken in conjunction with the accompanying drawings.